1. Field of the Invention
The present invention relates to inflatable dunnage air bags as are utilized in securing cargo and/or freight in a cargo hold, such as a truck, rail car, aircraft or ship and more particularly, to an inflation valve therefor.
2. General Background of the Invention
Inflatable air bags are utilized in the cargo transportation industry to secure a load against undue movement during the transportation phase. While cargo is generally loaded as snugly into a vehicle as possible, such as a cargo hold of a truck or rail car, it is frequently of sufficiently irregular shape or varied size, it is not otherwise possible to ensure a tight fit during the loading process
The transportation industry has adopted relatively large inflatable bags, often a plastic or rubber so as to be flexible and to readily conform to the irregular shapes of cargo loads. These bags are inserted into observable spaces in a load, and inflated with air to a pressure sufficient to keep the freight from shifting during the movement of transit, whether it be from swaying or being bounced vertically.
The dunnage bags are comprised of an inflatable bladder which is enclosed within an outer covering (also a bag) which protects the bladder from wear or puncture. The outer bags are frequently of fabric or paper. Bags may be of a variety of shapes and sizes, such that an appropriate shape or size may be fitted into the several voids that inevitably occur in a loaded container. Once fitted into the void, a bag/bladder is inflated with compressed air to a predetermined pressure level sufficient to prevent or retard the shifting or movement that otherwise occurs in travel.
One critical part of the dunnage bag is the valve which enables the rapid, facile inflation and deflation required in the loading and emptying of the container. Conventional construction includes the valve (a thermoplastic material) “welded” to the bladder so as to ensure a secure seal to retain the desired air pressure. The valve includes a generally tubular body portion which defines a conduit for the entry and exhaust of the pressurized air into and out of the bag. Within this tubular body is mounted a valve member which seats on a cooperating seal, usually a ring, the combination of which provides a tight joinder, particularly for the pressurized situation, to retain the pressurized air in the bag providing the desired load security against movement, and shifting. Many conventional valves are spring loaded to the closed position to facilitate the seal of the charged air, allowing also the manual depression against the spring to open the valve for natural deflation. Another common construction incorporates a hinged valve member that securely seats to form a seal. A number of patents are illustrative of the state of the art.
U.S. Pat. No. 4,579,141 Arf illustrates a valve for filling and discharging inflatable hollow bodies, in this instance a dinghy. The valve is self closing, as is conventional of valves for dunnage bags. The valve plate is spring loaded, to the closed position by radial leaves which cause the valve plate to bear on a sealing ring, when the valve is in the inactivated state.
U.S. Pat. No. 5,651,403 to Andersen shows a valve for sack, such as a dunnage bag, to be filled with pressurized air through a nozzle to the valve. The valve is hinged and opens the filling nozzle in relation to the sealing flange.
U.S. Pat. No. 6,823,905 to Smith, et al shows an alternative inflation valve for a dunnage bag having a flapper valve member which is affixed on a chordal segment of the circular valve opening. Opposite end portions of the fixation bar project radially inwardly toward each other so as to define detents for maintaining the valve in the open position.